Structure of the Lining Epithelium of the Cauda Epididymis of the Golden Hamster

The ductus epididymis has roles in the maturation and storage of spermatozoa. The main function of the cauda epididymis is the storage of spermatozoa; however, this region exerts other morphophysiological roles. So, this study was aimed at investigating structural features of the cauda epididymis epithelium, which could indicate roles other than the storage. The relative percentages of the cell types in the epithelium were 74.9, 6.9, 12.5 and 5.6% of principal, clear, basal and halo cells respectively. Large intercellular spaces were seen among the lateral plasmatic membranes of adjacent principal cells or among these cells and others cell types. These spaces were found to be filled with multivesicular bodies, myelin figures, scrolls and debris of membranes or flocculent dense material. Clear cells had the cytoplasms filled with lysosomes (3/4 of basal cytoplasm), and vacuoles and vesicles (1/4 of apical cytoplasm). The observations allowed us to infer that clear cells could act in the process of endocytosis and also in water transfer from the lumen to the interstitium through the epithelium compartment. Moreover, transcytosis may occur at the cauda epididymis of Golden hamster.

Ultrastructural features of the lining epithelium of the vas deferens of Agouti paca

The epididymal epithelium of Agouti paca, a wild South American rodent, was basically formed by principal and basal cells. Principal cells were closely related to processes of adsorptive endocytosis, phasefluid endocytosis and also secretion originating from their cytoplasmic ultrastructural features. Principal cells were also characterized by the presence of vesicles of several shapes, sizes and internalized content occurring in smaller pits, pale small vesicles next to the apical brush border of microvillus, as well as coated vesicles, smooth surface vesicles and great vesicles. Multivesicular bodies, endosomes and lysosomes were mainly observed in supranuclear position. Moreover, presence of an apocrine secretory process was demonstrated by the occurrence of apical cytoplasmic expansions projecting into the vas deferens luminal compartment. Basal flattened cells without luminal surface contact occurred next to the basement membrane of the ductus, and did no exhibit special ultrastructural features.

Morphological features of the epididymal epithelium of gerbil, Meriones unguiculatus

Principal cells of the ducts epididymis of the Mongolian gerbil showed ultrastructural characteristics of lining epithelium cells close related to processes of protein secretion, and transcytosis occurring between adjacent principal cells which were mainly verified in the initial segment. Principal cells also presented roles of fluid phase and adsorptive endocytoses, as well as autophagic and heterophagic lysosomal activities mainly observed in the caput epididymis. Columnar (principal) cells of the corpus epididymidis presented great number of variable vesicles and vacuoles distributed in all the cytoplasmic levels occurring a progressive coalescence pattern among them, which help to guarantee formation of cytoplasmic channels for fluid phase transport between the tubular lumen and epididymal interstitium. Clear cells were presented in the initial segment and predominately in the cauda epididymis epithelium of the gerbil and showed marked ultrastructural characteristics of endocytosis activities occurrence, perhaps directly related to the turnover of fluid phase of spermatozoa stored into the lumen of the distal tail. Other epididymal epithelium cells were verified and described such as basal, halo, apical and dark cells, but they did not presented special ultrastructural features. (c) 2007 Elsevier Ltd. All rights reserved.

Effects of chronic experimental alcoholism on the epithelium of the uterine horn of rats (Rattus norvegicus albinus)

Sixty adult tats (Rattus norvegicus albinus) of the same age (3 months) and with a mean body weight of 228 g were divided into two experimental groups. The control group received solid diet (Purina rat chow) and tap water ad libitum. The other (alcoholic group), received the same solid diet and was allowed to drink only sugar cane brandy dissolved in 30° Gay Lussac (v/v). At the end of periods of 90, 180 and 270 days of treatment, the animals were anaesthetized with ethyl ether during estrus, weighed and sacrificed. The final mean body weights were similar in the control and alcoholic groups. The results showed intense atrophy on the lining epithelium of the endometrium of uterine horns in the alcoholic group. Important ultrastructural epithelial alterations were also observed in the female alcoholic group, such as: intense lipid droplet accumulation, increased rough endoplasmic reticulum cisternae and mitochondrial size and presence of intraepithelial neutrophils. The secretory activity of these rats was reduced. Therefore, we concluded that alcohol acts as a toxin on the epithelial layer of the rat endometrium.

Ultrastructural features in the epididymis of the dog (Canis familiaris, L.)

The ultrastructure of the epididymal duct of the dog is described in this paper. The epididymis was divided into three morphofunctional segments: initial, middle and terminal. The cellular population of the lining epithelium is formed from principal, apical, basal and clear cells. The peritubular stroma and the tubular interstitium surrounding the epithelium are also described. The outcome is compared to the description made in other species of mammals.

IGFR-I expression and structural analysis of the hard palatine mucosa in an ethanol-drinking rat strain (UChA and UChB)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Oral glands in dipsadine ""goo-eater"" snakes: Morphology and histochemistry of the infralabial glands in Atractus reticulatus, Dipsas indica, and Sibynomorphus mikanii

Although snake infralabial glands are generally constituted of mucous cells, among dipsadines, they are much more developed and predominantly serous in nature, possibly due to the peculiar feeding habits of some species of this group, the ""goo-eaters"", which feed on soft and viscous invertebrates. We compared the morphology and histochemistry of the infralabial glands of three goo-eater species of Southeast Brazil, Atractus reticulatus, Dipsas indica and Sibynomorphus mikanii. In A. reticulatus the glands are formed by mixed acini composed of mucous and seromucous cells and in D. indica, they are composed of mucous tubules and seromucous acini. In S. mikanii the glands are organized in seromucous acini; mucous cells are restricted to the gland anterior region and to the duct lining epithelium. Ultrastructurally, secretory granule electron density varies from low to moderate, depending on their mucous or seromucous nature. The results indicate a large morphological and histochemical variation in the infralabial glands, probably reflecting differences in the secretion chemical composition and in feeding specialization among the three species. The protein content in the secretory cells can be related with the presence of toxins that can be used in chemical prey immobilization or detaching of snails from their shells. (c) 2007 Elsevier Ltd. All rights reserved.

Ultrastructure of the epithelium lining of cauda epididymidis in mongrel dogs

The epithelium lining of cauda epididymidis in mongrel dogs was examined by transmission electron microscopy. The epididymal epithelium is pseudostratified with stereocilia and is composed predominantly of principal and clear cells. Therefore, exist basal and apical cells. The principal and clear cells show features suggesting that they may be preferentially involved in absorptive and secretive functions. These results are compared with previously published data on the cauda epididymidis of other mammalian species, in order to understand the significance of the epididymis in sperm maturation.

deltaNp63 has a role in maintaining epithelial integrity in airway epithelium.

The upper airways are lined with a pseudostratified bronchial epithelium that forms a barrier against unwanted substances in breathing air. The transcription factor p63, which is important for stratification of skin epithelium, has been shown to be expressed in basal cells of the lungs and its ΔN isoform is recognized as a key player in squamous cell lung cancer. However, the role of p63 in formation and maintenance of bronchial epithelia is largely unknown. The objective of the current study was to determine the expression pattern of the ΔN and TA isoforms of p63 and the role of p63 in the development and maintenance of pseudostratified lung epithelium in situ and in culture. We used a human bronchial epithelial cell line with basal cell characteristics (VA10) to model bronchial epithelium in an air-liquid interface culture (ALI) and performed a lentiviral-based silencing of p63 to characterize the functional and phenotypic consequences of p63 loss. We demonstrate that ΔNp63 is the major isoform in the human lung and its expression was exclusively found in the basal cells lining the basement membrane of the bronchial epithelium. Knockdown of p63 affected proliferation and migration of VA10 cells and facilitated cellular senescence. Expression of p63 is critical for epithelial repair as demonstrated by wound healing assays. Importantly, generation of pseudostratified VA10 epithelium in the ALI setup depended on p63 expression and goblet cell differentiation, which can be induced by IL-13 stimulation, was abolished by the p63 knockdown. After knockdown of p63 in primary bronchial epithelial cells they did not proliferate and showed marked senescence. We conclude that these results strongly implicate p63 in the formation and maintenance of differentiated pseudostratified bronchial epithelium.

In vivo confocal microscopy of the palpebral conjunctiva and tarsal plate

Purpose The aim of this work is to develop a more complete understanding of the in vivo histology of the human palpebral conjunctiva and tarsal plate. Methods. The upper eyelids of 11 healthy human volunteer subjects were everted, and laser scanning confocal microscopy was used to examine the various tissue layers of the palpebral conjunctiva and tarsal plate. Results The superficial and basal epithelial layers are composed of cells with gray cytoplasm and thick, light gray borders.Nuclei can not be seen. The stroma has a varied appearance; fibrous tissue is sometimes observed, interspersed with dark,amorphous lacunae, and crevases. Numerous single white or gray cells populate this tissue, and fine blood vessels are seen traversing the field. Occasional conjunctival microcysts and Langerhans cells are observed. The tarsal plate is dark and amorphous, and meibomian gland acini with convoluted borders are clearly observed. Acini are composed of an outer lining of large cuboidal cells, and differentiated secretory cells can be seen within the acini lumen. Conclusions Laser scanning confocal microscopy is capable of studying the human palpebral conjunctiva, tarsal plate, and acini of meibomian glands in vivo. The observations presented here may provide useful supplementary anatomical information relating to the morphology of this tissue.

Stromal upregulation of lateral epithelial adhesions : gene expression analysis of signalling pathways in prostate epithelium

BACKGROUND: Stromal signalling increases the lateral cell adhesions of prostate epithelial cells grown in 3D culture. The aim of this study was to use microarray analysis to identify significant epithelial signalling pathways and genes in this process. METHODS: Microarray analysis was used to identify genes that were differentially expressed when epithelial cells were grown in 3D Matrigel culture with stromal co-culture compared to without stroma. Two culture models were employed: primary epithelial cells (ten samples) and an epithelial cell line (three experiments). A separate microarray analysis was performed on each model system and then compared to identify tissue-relevant genes in a cell line model. RESULTS: TGF beta signalling was significantly ranked for both model systems and in both models the TGF beta signalling gene SOX4 was significantly down regulated. Analysis of all differentially expressed genes to identify genes that were common to both models found several morphology related gene clusters; actin binding (DIAPH2, FHOD3, ABLIM1, TMOD4, MYH10), GTPase activator activity (BCR, MYH10), cytoskeleton (MAP2, MYH10, TMOD4, FHOD3), protein binding (ITGA6, CD44), proteinaceous extracellular matrix (NID2, CILP2), ion channel/ ion transporter activity (CACNA1C, CACNB2, KCNH2, SLC8A1, SLC39A9) and genes associated with developmental pathways (POFUT1, FZD2, HOXA5, IRX2, FGF11, SOX4, SMARCC1). CONCLUSIONS: In 3D prostate cultures, stromal cells increase lateral epithelial cell adhesions. We show that this morphological effect is associated with gene expression changes to TGF beta signalling, cytoskeleton and anion activity.

Polarized fluid movement and not cell death, creates luminal spaces in adult prostate epithelium

There are two predominant theories for lumen formation in tissue morphogenesis: cavitation driven by cell death, and membrane separation driven by epithelial polarity. To define the mechanism of lumen formation in prostate acini, we examined both theories in several cell lines grown in three-dimensional (3D) Matrigel culture. Lumen formation occurred early in culture and preceded the expression of cell death markers for apoptosis (active caspase 3) and autophagy (LC-3). Active caspase 3 was expressed by very few cells and inhibition of apoptosis did not suppress lumen formation. Despite LC-3 expression in all cells within a spheroid, this was not associated with cell death. However, expression of a prostate-secretory protein coincided with lumen formation and subsequent disruption of polarized fluid movement led to significant inhibition of lumen formation. This work indicates that lumen formation is driven by the polarized movement of fluids and proteins in 3D prostate epithelial models and not by cavitation.

Identification of GABA receptors in chick retinal pigment epithelium

Purpose: The retinal pigment epithelium (RPE) is a multifunctional, monolayer of cells located between the neural retina and the choroicapillaris. γ-Aminobutyric acid (GABA) is the most important inhibitory neurotransmitter in the retina and GABA receptors are known to be present in chick retina, sclera and cornea. There is a report of genes involved in GABA receptor signaling being expressed in human RPE, however, whether GABA receptors are present in chick RPE is unknown. Methods: Real time PCR and western blot were used to determine the expression of GABA receptors (alpha1 GABAA, GABABR2, and rho1 GABAC receptors) in isolated chicken RPE. Immunofluorescence using antibodies against one of the GABA receptor sub-types was used to determine receptor localization. Results: Both real-time PCR and western blot demonstrated that alpha1 GABAA, GABABR2 and rho1 GABAC receptors were expressed in isolated chick RPE. Immunofluorescence further demonstrated that GABA receptors were localized to the cell membrane and plasma of RPE cells. Conclusions: Alpha1 GABAA, GABABR2 and rho1 GABAC receptors were expressed in chick RPE. The purpose of the GABA receptors within the RPE remains to be explored.

Epithelial-mesenchymal interconversions in normal ovarian surface epithelium and ovarian carcinomas : an exception to the norm

Cancer that arises from the ovarian surface epithelium (OSE) accounts for approximately 90% of human ovarian cancer, and is the fourth leading cause of cancer-related deaths among women in developed countries. The pathophysiology of epithelial ovarian cancer is still unclear because of the poor understanding of the complex nature of its development and the unusual mechanism(s) of disease progression. Recent studies have reported epithelial-mesenchymal transition (EMT) in cultured OSE and ovarian cancer cell lines in response to various stimuli, but our understanding of the importance of these observations for normal ovarian physiology and cancer progression is not well established. This review highlights the current literature on EMT-associated events in normal OSE and ovarian cancer cell lines, and discusses its implication for normal ovarian function as well as acquisition of neoplastic phenotypes. The pathological changes in OSE in response to EMT during neoplastic transformation and the contribution of hormones, growth factors, and cytokines that initiate and drive EMT to sustain normal ovarian function, as well as cancer development and progression are also discussed. Finally, emphasis is placed on the clinical implications of EMT and potential therapeutic opportunities that may arise from these observations have been proposed.